Apparatus for heating motor vehicles



y 16 1939. A. R. UNTERN 2,158 758 APPARATUS FOR HEATING MOTOR VEHICLES Filed on. 2, 1936 Sheets-Sheet 1 z lffrlll/ll/ 1,11

6'4 E E 4 INVENTOR )Z zz'nfarz 9' A TTORNE K5.

May 16, 1939. A. R. LINTERN 2,158,758

APPARATUS FOR HEATING MOTOR VEHICLES I Filed Oct. 2, 1936 2 Sheets-Sheet 2 INVENTOR filfred 72 1522562 2 A TTORNE V6- 1 flwam 45 substantially uniform temperature.

, Patented May 16, 1939 Alfred B. mam, lliela, lsllfllbl' a Evans Products company. Den-cit,- Mich, a corporation of Delaware.

Application mm 2, 1m, sci-a1 No. 103,641 3 Claims. (01. 237-123) This invention relates to vehicles and in particular relates to apparatus for ventilating the interior of the vehicles with fresh warm air.

Objects of this invention are to heat air be- 5 fore introducing it into the passenger compartment of a vehicle by an arrangement of an exhaust heater and a water heater in which the heating effect of'one supplements that of the other so that the air introduced into the passenger compartment is substantially uniform in temperature at all times; to so arrange the exhaust heater and the water heater relative to each other and with the means which forces 'the air through the heater that the air disl5 chargedv from the hot water heater assists in drawing the air through the exhaust heater without loss of air volum due to friction of the exhaust heater; to provide a heating assembly which may conveniently be installed on conventional vehicles with a. minimum of alterations, and to provide a rugged structure which is economical to manufacture and install.

Other objects of the invention will become apparent from the following specification, the drawings relating thereto and from the claims hereinafter set forth. v

In the drawings, in .which like numerals are used to designate like parts in the several views throughout: Figure 1 is a side elevational view with a part broken away embodying features of the present invention;

' Fig. 2 is an enlarged vertical cross-sectional view of structure illustrating an embodiment of the present invention;

Fig. 3 is a cross-sectional view taken substan tially along the 'line 3-4 of Fig. 2 and Fig. 4 is a cross-sectional view taken substantially along the line 4-4 of Fig. 2.

The present invention particularly relates to apparatus for use on large commercial passenger vehicles; and in such vehicles in cold weather it is necessary to constantly supply the passenger compartment with fresh warm air of a cut invention provides for heating the air before it is injected into the passenger compartment by passing it through an exhaust heater and a hot water heater, each of these heaters so being so arranged relative to each other that they supplement each other in heating effects so that the air enteringthe vehicle is substantially uniform in temperature. Hot water heaters, in which the heating water is supplied from the water cooling system for the engineyare most The preshicle is operating at relatively low speed; and exhaust heaters are most efficient when the vehicle is operating at high rates of speed. By passing a portion of the air to be heated through a hot water heater, and the other portion through an' exhaust heater and uniting them in a common discharge conduit before discharge into the passenger compartment it can be seen that each heater will supplement the other one eflieient when the vehicle is idling or the veto give a balanced and uniform heating eilfect on the air discharged into the passenger compartment. That is, for example, when the vehicle is-operating at a high rate of speed although the water heater is least eflicient under eflicient and underthis condition the air passing through the exhaust heater will be heated to a greater extent than the air passed through the hot water heater; and when these two streams are intermingled in a common conduit a mean temperature is reached which will be substantially uniform for various speeds of operationof the vehicle.

In the present invention after the air has been passed in separate stream through the hot water heater and the exhaust heater, respectively, it is joined in a common chamber and, conduit which discharges into the interior of the vehicle. When one ofthe separated streams is passed through the exhaust heater, there is a tendency to reduce the air volume passing through the exhaust heater because of the friction of the relatively restricted exhaust heater passages. In the present invention, the common' discharge chamber is provided with a restricted area in the path of the stream from the hot water heater; and the stream from the exhaust heater enters the common chamber adjacent the end of this restricted area. The effect of this arrangement is that the stream of air passed through the hot water heater and the restricted area expands upon leaving the restricted" area and creates a relatively low pressure in the common chamber adjacent the point at which the .stream of air from the exhaust heater is discharged thereinto. As there is a relativehr highdrawing the air from a region immediately above the. roof adjacent the forward wall of the vehicle as at this regionthe air is freest from such foul contaminating gases.

Referring-to the drawings, in Fig; 1 a large passenger vehicle I. is illustrated embodying the preferred features of the present invention. The vehicle ll comprises a roof portion l2, at forwardly facing wall it, including a windshield, and side walls I! forming a closed body having a passenger compartment inside with a floor portion It. An air heating unit ll is provided preferably under the floor portion It adjacent the front of the vehicle close to the region at which the engine (not shown) is located. Fresh outside. airis conducted to the heater from a point above the roof 1! adjacent the front of the vehicle by-means of a conduit which is preferably located adjacent one side of the vehicle and extends through the roof, the top portion of the conduit having a projecting portion 22 with a forwardly facing opening immediately above the roof L. After the air has been heated in the heaters, it is discharged into the passenger compartment through? a conduit 24 extending longitudinally of the vehicle within the passenger compartmentand having suitable at spaced intervals along the length} of the conduit. The conduits it and 14 com I tivelmin the floor portion It for purposes to be more fully described hereinafter.

an heating unit is is preferably mounted under the floor portion it immediately beneath the openings 28 and II in the floor portion and is concealed from view bythe side or apron ii. The heating unit ll issubstantially rectangular in cross section and comprisu a top portion 2. having openings formed by upstanding flanges which are complementary in shape and fit within the openings 23 and II, respectively. The top portion 28 is provided with a downwardly extending peripheral flange II which flts over and is in secure engagement with the upper edge of a main casing portion 82 of the heater unit. The main casing portion 32 includes side walls 88, 84, II and It and a bottom wall 81 forming a closed unit within which the ducts and-h ating means, to be hereinafter described in eater detail, are'located.

In order to provide within the interior of the casing an inlet compartment and an outlet compartment, a transversely extending bailie :0 extends from beneath the floor portion IO/between the'openings 28 and II downwardly within the casing $2 for a substantial distance. The bailie 38 comprises a substantially U-shaped metal member ll forming spaced walls between which insulation 12 is provided.

An air inlet compartment 44, in communication with the duct II, is provided within the easing by the bailie 38 and has located therein an induction fan ll, of suitable known construction, which is driven by a motor The fan 46 is encloud within the chamber M by means of a casing I having an opening I2 therethrough in operative alignment with the fan It through which air .is drawn from the inlet chamber 44 into and through the induction fan. The bottom portion of the casing I is flared outwardly as at I and forms the upper .conflning wall .of a chamber It into which the air drawn by the fan is discharged.

-I'rom the'chamberli theair is separated into a pair of separate streams, one of the streams unicate with openings 23 and II, respecpassing through an exhaust heat exchanger it and the other of the streams passingthrough a hot water heater 0', in a manner to be described. In order to reduce turbulence in air flow, transversely extending curved plates I! are mounted adjacent the corners of the chamber It.

A discharge chamber 02 communicating with the discharge duct 24 is formed by the baflie a heater 0. includes inlet and outlet hot water,

pipes Cl and of which are suitably connected to the water cooling system of the engine in a manner well known. The inlet pipe 64 communicates with a header I! which is connected by means of transversely extending tubes II to an opposite header II, with which the outlet pipe 86 is in communication. Heat conducting fins Ll are arranged in the hot water heater structure in heat transfer relation with the tubes II and extend longitudinally of the discharge cham-.

ber 62 forming air passages therebetween for the air stream to be heated by the hot water heater.

To provide a conduit for the other of the pair of air streams, an opening II is provided in the wall ll communicating with the chamber li and over which an elbow conduit ll having flanged portions 82 is suitably secured to the outer face of the wall II. A reversely directed elbow conduit ll communicates with the outlet end of the conduit OI and is in communication with the interior of theexhaust heater I through a suitable opening in the casing of the exhaust heater. An exhaust conduit is which extends from the vehicle engine in the usual way extends through the casing of the exhaust heater it which encloses a portion of the exhaust pipe ll. air from the conduits ill and it passes into and through the exhaust heater II in intimate heat exchange relation with the exhaust pipe OI, and is discharged from the exhaust heater ll through an opening in the exhaust heater casing through a flexible conduit 81 from which the air is discharged into the discharge chamber 82 through an opening II in the wall ll. The conduit 81' is provided with suitable flttings l. and 02 adjacent its ends communicating the conduit It with the interior of the exhaust heater and th chamber 82, respectively. I

- As there is a tendency to retard that stream of air passing through the exhaust heater because of the friction of the relatively restricted passages therein, the volume of air passing through the exhaust heater would be reduced by this friction. In order that the air passing through the exhaust heater will not be reduced in volume due to friction, a relatively restricted area 'is created within the common discharge chamber '2 in the path of the stream from the hot water heater. By restricting this area and then enlarging the area relative to'the area of the passage through the hot water heater adjacent the point at which the stream of air from the exhaust heater is discharged into the common chamber 82, a relatively low pressure is created adjacent the outlet end of the exhaust conduit which assists in drawing the air through the exhaust heater without loss in volume.

extending transversely of the chamber 82 andanaemia curved downwardly to a point adjacent the top or the opening and forming one confining 'In order to reduce heat losses through the casing 32 in the region of the discharge chamber 62 and in' the region of'the location of the exhaust oi the hot water heater. spaced wall members I02 are provided between which and the outer walls oi the casing 32 insulating material I04 is placed.

The restricted area above referred to is that area immediately above the hot water heater III which is defined by, the plate members l00 and I02. Referring particularly to Fig. 4, it is evident that this area is restricted as compared to the area of the passagethrough the hot water heater. This area is then enlarged immediately above the top edge of the member I00 so that a relatively low pressure is created adjacent the outlet of the exhaust conduit 96. This enlargement is defined-by that portion of the member 98 above the top edge of the member 100 and the plate I02.

In order to provide a simplified structure for the exhaust conduit 24, the exhaust conduit is v formed by utilizing an inner side wall panel I06 7 adjacent the bottom thereof as one of the con- "26 are preferably provided in the downwardly extending portion 2 at suitably spaced intervals along the length of the conduit 24, but it is to be understood that-such openings could also a be provided in the horizontal portion I09 if de-- sired.

In operation, air is caused to enter the single conduit 20 either by the forward movement of the vehicle or by the fan 40 or by both and passes downwardiythrough the conduit 20 into the inlet chamber 44. From the inlet chamber 44 the air is drawn by the fan 40 through the fan and into the common chamber '56 from which it is divided into a pair of separate streams. One of the separate streams passes through the hot water heater in intimate heatexchange relation therewith into the discharge chamber 02; and the other separate stream passes outwardly through the opening 18 to and through the exhaust heater 58 and is discharged into the discharge conduit through the chamber 96. The two separate streams of air are intimately intermingled within the chamber 62 and are discharged from this chamber through the opening '35 into the" conduit 24 and from the conduit 24 into the interior of the passenger compartment.

As discussed above, for different vehicle operating conditions the heating efiects or efllciences of the hot water heater and the exhaust beater surate with the appended claims.

vary considerably; For example, during low speeds or operationthe hot water heater is'most efiicient so that the air passing therethrough is heated to a greater extent than when the vehicle is operatingat high speed; while at low speeds of operation'the exhaust heater is least eillcient and does not heat the air to .the same extent as it does when the vehicle is operating at high speeds. As underone condition of operation one of the heaters is most efiicient while the other is least eflicient, and for a difl'erent condition of operation the other heater is most efllcient while the first heater is least efiicient, it is evident that the heaters supplement each other under the various conditions of operation; and by interminglingthe two separate streams of air before discharge into the passenger compartment, it is evident thata substantially uniform temperature of the air discharged into the passenger compartment may be maintained with the consequent uniform maintenance of temperature within the passenger compartment.

Formal changes may be made in the specific .embodiment of the invention described without departing from the spirit and substance of the broad invention, the scope of which is commen- What Iclaim is:

- 1. In combination, an automotive vehicle having a closed body, and an engine, means forming an air confining conduit communicating with the exterior of the body, means forming an air confining conduit communicating with the interior of the body, a pair of separate conduits connecting said first andsecond named means, one of said pair of. conduits including anexhaust heat exchanger which derives its source of heat from the exhaust products of the engine and the other of said pair of conduits having located therein a water heat exchanger which derives its source of heat from the cooling system of the engine, and means to force air into said body through said first and second named means and through said pair of conduits in heat exchange relation with said heat exchangers.

4 2. In combination, an automotive vehicle having a closed body and an engine, a first conduit forming an air confining passage therethrough including an exhaust heat exchanger which derives its source of heat from the exhaust products of theengine, a second conduit forming an air confining passage therethrough having lo-- cated therein a water heat exchanger which derives its source of heat from the cooling system of the engine, said first and second named conduits being arranged in-paralle1, means forming a common air inlet conduit for said first and second conduits, means forming a common discharge conduit for said first and second conduits communicating with the interior of the body,

means communicating said first conduit with said.

last named means beyond the region of communication of said second conduit with the last named means, and means to force air into the body through said pair of conduits and said first and second named means in heat exchange relation with said heat exchangers.

3. In combination, an automotive vehicle having a closed body and an engine, a first conduit forming an air confining passage therethrough including an exhaust heat exchanger which derives its source of heat from the exhaust products of'the engine,-a second conduit forming an air confining passage therethrough having located therein a water heat exchanger which demember communicating said'first conduit with said last named means beyond the region of communication of said second conduit with said last named means, said member being so constructed and arranged that the discharge of air from the second conduit creates a relatively lowpressure within said last named means compared to the air pressure within. the first conduit to assist the passage of air through said exhaust heat exchanger, and means to force air into the body through said pair of conduits and said first and second named means in heat exchange relation with said heat exchangers.

mannnm'man. 

